/**
 * @param {number[]} nums
 * @return {number}
 */
var unequalTriplets = function (nums) {

};






// 回溯

/**
 *   let count = 0, set = new Set(), arr = []
  bc(0)

  function bc(index) {
    if (arr.length == 3 && set.size == 3) {

      count++
      return
    }

    for (let i = index; i < nums.length; i++) {
      if (set.has(nums[i])) continue
      arr.push(nums[i])
      set.add(nums[i])
      bc(i + 1)
      arr.pop()
      set.delete(nums[i])
    }
  }
  return count
 */

